Test amm by pulling connector off the amm (remove with ignition OFF, and key preferably removed from car). See if it runs better with amm disconnected. If so, that's your problem. Reconnect amm with ignition OFF.

If replacing the amm, there's a 3-digit number at the end of the part ID number. Common numbers are 001, 007, 016. '86 amm is usually (always??) a ...007. Just remember James Bond. Look it up at fcpgroton.com under Fuel Injection parts.

If airbox thermostat fails and heater tube from manifold is intact, that will kill the amm by overheating it. So don't pull amm from a junker with the tube/hose intact.
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Sven: '89 245 NA, 951 ECU, expanded air dam, forward belly pan reaches oem belly pan, airbox heater upgraded, E-fan, 205/65-15 at 50 psi, IPD sways, no a/c-p/s belt, E-Codes, amber front corner reflectors, aero front face, quad horns, tach, small clock.